During drilling, a drilling mud is used to help cool the drill bit and flush debris from the well bore. The drilling mud can cause additional friction between the mud and the bore hole wall and the mud and the metal components of the drilling operation, such as the casing, drill pipe and drill bit. This additional friction slows the drilling operation by reducing the drilling rate and the rate of penetration. The additional friction also reduces the variability of the drilling operation itself, in particular the degree of well bore deviation that may be drilled.
A silicate-based mud has a high coefficient of friction against rock or metal when compared to an oil-based or a synthetic-based mud, which is a drilling mud based on a synthetic hydrocarbon oil. However, the oil-based and synthetic-based mud presents certain environmental concerns and wells in certain locations may not be drilled using the lower friction mud. In addition, a synthetic-based mud is typically much more expensive than a silicate-based mud, making the mud based on a synthetic hydrocarbon oil economically less desirable. A silicate-based mud is preferred environmentally but exhibits a high coefficient of friction between the mud and the well bore and metal components. Typically a more traditional silicate-based mud has a lubricity measuring in the range of 0.3 or higher. It is desirable to lower the coefficients of friction in order to increase drilling rates and the rate of penetration. An additional advantage to a mud having a lower coefficient of friction is that it can be used in drilling a deviated well bore.